<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        /* 元素选择器 */
        h1
        {
            color: red;
            font-size: 12px;
            /* font-size: 有最小值; */
        }
        /* 类选择器 */
        .test
        {
            color: red;
            background-color: salmon;
            text-align: center;
            line-height: 100px;
        }
        .img
        {
            width: 400px;
            height: auto;
        }
        /* id选择器 */
        #idtest
        {
            color:royalblue;
        }

    </style>
</head>
<body>
    <h1>hello，world</h1>
    <div class="test">hello，world</div>
    <div id="idtest">hello，world</div>
    <img class="img" src="/Users/zyc/Desktop/git/晓舟前端开源/zyc_html/zyc-webpage-reconstruction/lanmao.jpg" alt="">
</body>
</html>